Just collected my car from it’s MOT and see the certificate doesn’t take into account the unexpired time of the last certificate. I rang up and it’s because the unexpired amount is over a month – if it had less than a month left then it would have been added onto my new certificate. Why is this?

I had this – they can only forward date a certain number of days but didn’t tell me when I booked in so I ‘lost’ a months mot.

Why is this?
http://www.direct.gov.uk/en/Motoring/OwningAVehicle/Mot/DG_4022112

Cause you took it in to early

That is the rule IIRC. I presume it’s because they could end up giving you an MOT for over 13 months if they didn’t restrict it. That would be seen as too long between MOT tests.

Well no they could give you up to 13 months which would seem logical – wish they had told me at the garage beforehand!

yep, it’s to keep the tolerance down so you don’t end up having one MOT valid for like 18 months or something. they have to set a limit, so it’s a month. i.e. you can take the MOT upto a month before it’s due, and post date it to a year from when it was effectively due.

I thought it was fairly common knowledge – doesn’t it say on the MOT cert?

it does, but in my case it was a car that had never had an mot before so I didn’t have anythgin to go by.